In general, fundamentals for the photographic process of a silver halide color photographic light-sensitive material consist of a color development step and a desilvering step. In the desilvering step, the developed silver produced in the color development step is oxidized, to become a silver salt, by the action of an oxidant (a so-called bleaching agent), and further, the silver salt is dissolved and removed from the light-sensitive material, by an agent capable of dissolving a silver ion (a so-called fixing agent).
As the bleaching agent used in the above desilvering step, iron(III) complex salts of organic acids, and particularly iron(III) complex salt of ethylenediamine-N,N,N',N'-tetraacetic acid (hereinafter abbreviated as EDTA), have long been used, and, in view of rapid processing and the reduction of waste liquor components of processing solutions, iron(III) complex salt of 1,3-propanediamine-N,N,N',N'-tetraacetic acid (hereinafter abbreviated as 1,3-PDTA) is also widely used.
However, under the recent increase in consciousness toward earth environmental preservation, strong attention is being given to the discharge of the above chelating agents, which are low in biodegradability in nature and tend to solubilize harmful heavy metal ions, the development of substitutes for them is desired. Some chelating agents having good biodegradability are described, for example, in JP-A-4-313752 ("JP-A" means unexamined published Japanese patent application), 5-265159, and 6-161065.
On the other hand, with the propagation of small-scale store processing laboratories (photofinishers), which are called mini-labs, processing in the shortest possible period by using automatic processors that are as small as possible is demanded continuously and strongly. In this regard, it is rather advantageous to carry out the desilvering step by using a processing solution in which a bleaching agent, for oxidizing silver, and a fixing agent, for solubilizing silver ions, coexist in the same bath, that is, using a bleach-fix solution.
However, when processing is carried out continuously for a long period of time by using a bleach-fix solution in which, as a bleaching agent, an iron(III) complex salt of a chelating agent excellent in biodegradability, is used, it is observed that dirt (stain) is apt to adhere to the processed light-sensitive material also, the image part of the light-sensitive material, with time after being processed, is apt to be easily discolored with, for example, a stain.